Breaker point mechanism



March 15, 1949. A. l.. BRowNLEE Er AL 2,464,779

BREAKER POINT MECHANISM Filed Sept. 21. 1945 WQ j 4 3 o y /2 /0 4 3 K) 25 2 I l'/ -r 2 4 V ,li-gil 26 20 24] Z7 Y 5 27 fi p 2 4 3 fam/Anon q1- ATTORNEYS Patented Mar. 15, 1949 BREAKER POINT MECHANISM Allen L.` Brownlee, West Springfield,'and-A1bert I..A1s.trom, Longmeadow, Mass., assignors to Wico Electric Company,A West Springfield, Mass., a corporation of Massachusetts ApplicationSe'ptember 21, 1945, Serial No.617,8,44A

(Cl. d-30)? 2 Claims.

This invention relates to improvements in breaker point mechanisms, such as. are used for timing the ignition sparks in internal combustion engines.

The. invention has for its generaly objects to provide a breaker point mechanism of the reciprocating type which is simple in construction, relatively inexpensive to manufacture, compact, readily adjustable and calculated to have a long life..

A particular object of the invention is to provideY a mechanism of the class described in which a reciprocating plunger, carrying one of the breaker points, is. reciprocable in a groove in a support and the other breaker point is carried by a member which serves to. conne the plunger in its-"groove-the arrangement providing an exceedingly compact structure capable of being mounted within narrow space limits.

Another object of the invention isv to provide in a mechanism of the class described a reciproeating breaker-point-carrying plunger, a rotatable cam engaging one end of the plunger for reciprocatingthe same and a condenser'mounted adjacent the other end of the plunger,the axes of `the cam and condenser being parallel and at right angles to the path of reciprocation of the plunger and said axes and path being located in a common plane.

Another object is to provide a means, carried by the same part which guides the reciprocating plunger, forA wiping the cam and lubricating the same and the plunger.

A further object is to provide meansfor moving-the member which retains theV reciprocating plunger in its groove, inthe direction of reciprocation of the plunger for the purposev of lenabling adjustment of the breaker points.

The invention will be disclosed with reference to the accompanying drawings in which- Fig. 1 is an enlarged plan view of breaker-point mechanism embodying the invention;

Fig2 is an enlarged sectional elevational View thereof Figs. 3, 4 and 5 are enlarged cross sectional views taken on the lines 3 3; 4--4 and 5--5,

respectively, of Fig. 1;v and Fig. 6 isl an enlarged fragmentary `ViewY taken similarly vto Fig. 2 and showing a modification. Referring to these drawings; I `represents a support for. the breaker point mechanism.Y This support may be of any suitable form. As shownr ithas a hub 2 through which a drive shaft 3, carl ryinga cam 4, extends. In this particular case, thesupport is thestator plate. of a flywheelmagneto and is shownin` part only. Thev hub 2 of the pla-te enci-rcles a hub 5 on the crankcase 6 of an engine and the shaft 3 is the engine crankshaft. However, the particular form of the support is not material to the present invention.

The support l has a part 'I projecting therefrom and this part is provided with a groove to slide-bly receive a plunger 8 which is of rectangula-r-cross sectional shapey and preferably"constructed of insulating material.` A member 9 isr fixed to part 'Lf'covering theA top of the slot and serving as a gib to confine the plunger 8 in its groove. The plungeris free to slide in a radial direction with respect to thel shaft 3 and its inner end'is adapted'to engage the outer peripheral surface of cam '4. A flat spring IG, xed as indicated at one end to `support I, has its other end engaged with the outer end of plunger 3 and yieldingly holds vthe linner end ol the plunger f Y against cam 4.

rEhe plunger vil carries near itsv other and outer end a breaker point II. A :cooperating breaker point -I2 is fixed to-member 9 and located in the pathloi movement of breaker point III. As herein shown, the outerporticn of plunger 8 has a recess I3 and the outermost Vertical wall of this recess carries the breaker vpoint .II. The member 9 has its outerend turned downwardly, as at III, into therecess i3v and the breaker point I2 is carried by the outer falce of the part I4. The'spring I il tends to hold l'the breakerpoints II and I 2 in .engagement and the cam l periodically moves thexplunger'radially outwardv to separate the. points. The member...9,:the'` part TI and the support I are of 'conducting.material and .serve .as .a groundconnection for the relativelygxed breaker point fI2.y The breaker point lI iselectrically connected byyany suitable dex-- ible conductor I5 to any suitable. insulated terminaL-in this case tothe insulated terminal IG of a'condenserI'I. This condenser, in the form herein shown, is cylindrical and is located just beyond the outer limit of thev stroke of. plunger 8 with its axis paralleling that of shaft 3. The axes of shaft 3 and condenser II lie 4in the same radialv plane as the longitudinal axis of plunger 8. One end of .the condenser sets into a lsocket I8 in support l. The condenserhas iixedv to its metal shel-l'a conducting lband I9 towhich is fixed an ear 20 and the latter is held by a lscrew 2Iv to the support` i... Itwillbe-understood that the metal shell of condenser I'I servesfas one terminal thereof and suchterminal is grounded by If desired and as indicated in Fig. 6, the plunger return spring can serve also as the electrical conductor for the movable and insulated breaker point II. Thus, a spring 22, fixed to the insulated terminal I6 of the condenser II may bear on the outer end 23 of the stud to which the breaker point I I is secured.

The member 9 has nished parallel straight side edges 2d which closely t the corresponding vertical walls of a shallow groove which is formed in part I and into which the member 9 lits. These sides and walls parallel the path of reciprocation of the plunger. In the member 9 is an elongated slot 25, also paralleling said path. A single cap screw 26 passing through the slot and threaded into part 1, serves to hold the member 9 to said part. By loosening screw 26, the member 9 may be moved in or out along the path of reciprocation of the plunger 'I for the purpose of adjusting the breaker points. Thus, with the cam 4 positioned to hold the plunger 'I in its outermost position, a feeler gauge may be inserted between the points 6I and I2 and the member 9 moved until point l2 engages the gauge and the latter engages point lI. Then screw 255 is set up to hold member 9 and point Ii in their adjusted positions.

The part 'l may also serve to support a iiexible member 2l such as a piece of felt, which engages the outer peripheral surface of cam I for the purpose of wiping this surface clean and also lubricating it and the plunger l. Some lubricant from the cam will pass along the sides of the plunger and enter the groove to lubricate the relatively sliding surfaces. The wiper may be supported by having one end inserted in a groove in the inner vertical wall of part 'I.

In operation, the inner end of the plunger 8 is held against cam 4 by spring le, and when such end leaves the high peripheral part of the cam, the points II and I2 will be engaged and, when such end is engaged by the high peripheral part of the cam, the breaker points will be separated. As the cam revolves, the flexible member 21, which is saturated with oil, wipes the peripheral surface of the cam, cleaning and lubricating the same. Lubricant, carried by the cam, reaches the inner end of the plunger 8 and some of it travels along the sides of the plunger and lubricates the latter in its slideway in the part 1.

The condenser I'I is bridged across the breaker points I I and I2 in the usual manner and for the usual purpose. Conveniently, the shell of the condenser forms one of its terminals and such terminal is connected to the breaker point I2, through the metallic support I, the part 'I and member 9 and grounded to the engine crankcase 6 by means of the support I and hub 2. A single exible conductor interconnects the insulated breaker point II and the insulated terminal I6 of the condenser. If desired, the return spring for the plunger may serve also as the exible conductor, as suggested in Fig. 6.

The construction is exceedingly simple and relatively inexpensive to manufacture. The two grooves in the part 'I, one for plunger 8 and one for member 9, may be machined at the same time by a single milling cut. The plunger 8 may be made of molded impregnated canvas phenolic material. The remaining operations consist of drilling and tapping holes and fastening the breaker points to their respective supports land these are simply and easily performed.

The construction is characterized by its compactness. which enables it to be mounted in space limits so small that breakers of conventional form cannot be used. The drawings show the mechanism twice actual size. By making the plunger retaining member 9 also serve as a support for the iixed breaker point II, the overall length oi the mechanism is kept within small limits. The width of the mechanism need not be greater than that of the part I which slidably supports the plunger 8. The cam 4 is arranged at one end of the plunger and the condenser II at the other. By having the axis of the condenser parallel that of the shaft, radial saving of space is eiected. The entire mechanism, including cam, breakers and condenser, may be slightly less than three inches in length or radial extent and the maximum width, excluding the cam, is slightly less than three quarters of an inch. The construction is well adapted to fit in the narrow radial space between the two core structures of the stator plate of a small iiywheel magneto, as pointed out in our copending application Serial No. 617,845, Pat. No. 2,447,727, Aug. 24, 1948, led on even date herewith.

The breaker points are conveniently accessible for easy adjustment when required. They are exposed from the top so that they not only can be inspected but so that a ieeler gauge can readily be inserted between the points. Also, the adjustment of member 9 is accessible for convenient use. A single screw holds this member in place and when loosened, allows the member to be slid in its ways in part 1 to effect the desired adjustment.

The invention thus provides an improved breaker mechanism which is simple, compact and may be manufactured in quantities at low unit cost and which is also elicient in operation and calculated to have a long life of useful service.

We claim:

1. Breaker point mechanism, comprising a support having a projecting part provided in its outer end with a relatively wide and shallow groove of rectangular cross section and a relatively deep and narrow groove which is also of rectangular cross section and which extends from the bottom of the first-named groove inwardly into said part, said grooves each having two parallel side walls and the side walls of each groove being parallel with the side walls of the other, said grooves each having a bottom wall and these bottom walls being in spaced parallel relation, a reciprocable plunger of the same rectangular cross section as the second-named groove and having a bottom wall and two parallel side walls closely fitting and slidably engaging the bottom wall and side walls respectively of the relatively deep and narrow groove, said plunger projecting beyond both ends of said part and having fixed to one projecting end a breaker point, a thin flat member in the relatively wide and shallow groove having a bottom wall in part resting on the bottom wall of the first-named groove and in part overlying and closing the second-named groove and having two parallel side edges which closely t and slidably engage one with each of the side walls of the rstnamed groove, the said overlying portion of the bottom wall of said member slidably engaging the top wall cf the plunger and serving as a gib to hold the plunger in its groove, said member projecting beyond one end of said part and carrying a breaker point adapted to be engaged with and disengaged from the breaker point on the plunger as the latter moves back and forth, said member having a slot therein paralleling the sides of said grooves, a screw passing through said slot and threading into said part and clamping said member against the bottom of its groove, said member when said screw is loosened being manually movable in the direction of reciprocation of the plunger to adjust the position of the stationary breaker point, the other end of said plunger adapted to be engaged and periodically moved in one direction by a cam to separate the breaker points, and a spring for moving the plunger in the other direction and holding the breaker points engaged.

2. Breaker point mechanism, comprising a support having a projecting part provided in its outer end with a relatively wide and shallow groove of rectangular cross section and a relatively deep and narrow groove which is also of rectangular cross section and which extends from the bottom of the rst-named groove inwardly into said part, said grooves each having two parallel side walls and the side Walls of each groove being parallel with the side walls of the other, one side wall of each groove lying in the same plane, said grooves each having a bottom wall and these bottom walls being in spaced parallel relation, a reciprocable plunger of the same rectangular cross section as the secondnamed groove and having a bottom wall and two parallel side walls closely fitting and slidably engaging the bottom wall and two side walls respectively of the relatively deep and narrow groove, said plunger projecting beyond both ends of said part and having fixed to one projecting end a breaker point, a thin ilat member in the relatively wide and shallow groove having a bottom wall in part resting on the bottom wall of the first-named groove and in part overlying and closing the second-named groove and having two parallel side edges which closely t and slidably engage one with each of the side walls of the rstnamed groove, the said overlying portion of the bottom wall of said member slidably engaging the top wall of the plunger and serving as a gib to hold the plunger in its groove, said member projecting beyond one end of said part and carrying a breaker point adapted to be engaged with and disengaged from the break point on the plunger as the latter moves back and forth, said member having a slot therein paralleling the side walls of said grooves, a screw passing through said slot and threading into said part and clamping said member against the bottom wall of its groove, said member when said screw is loosened being manually movable in the direction of reciprocation of the plunger to adjust the position of the stationary breaker point, the other end of said plunger adapted to be engaged and periodically moved in one direction by a cam to separate the breaker points, and a spring for moving the plunger in the other direction and holding the breaker points engaged.

ALLEN L. BROWNLEE. ALBERT I. ALSTROM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATESv PATENTS Number Name Date 1,084,645 Lehman Jan. 20, 1914 2,261,158 Holliday Nov, 4, 1941 2,384,828 Fuston Sept. 18, 1945 FOREIGN PATENTS Number Country Date 521,224 France July 8, 1921 

